This is a phase II, randomized, double-blind, placebo-controlled study to evaluate the weight loss effects of daily subcutaneous administration of A-100 in obese subjects. Participants will be taught to self-inject starting at the part B visit during the screening period. After screening, eligible subjects will be randomized to 2ml A-100, 4ml A-100; 2ml placebo, in a 2:2:2:1 ratio. This study is expected to last approximately 12 months, with an 8 month study duration for each participant. Participants will be monitored with physical exams, dietary intervention and behavior modification, body composition, and periodic laboratory analysis.